287] STUDIES ON MYXOSPORIDIA—KUDO 49 



The sporoplasm occupies the extracapsular cavity at the posterior 

 region of the spore. It is of granular structure with almost always two 

 nuclei. Besides, it has an iodinophilous vacuole mostly round or oval in 

 the spores of the family Myxobolidae. It occurs thruout the spore stage 

 and is the important character of the said family. The contents of the 

 vacuole is probably of glycogenous nature and is stained deeply with 

 iodine. Small refringent fat globules have also been observed in the spore. 



Davis (1917:212) proposed to use capsular and postcapsular sides in 

 place of anterior and posterior ends which have most frequently been 

 used and are also used in the present paper. The latter terms can be 

 employed as properly as Davis' terms except in the case of the Myxidiidae, 

 where both terms, strictly speaking, are inapplicable. 



Tho various abnormal spores are very often encountered in several 

 species, the majority of the spores are of typical form, structure and size. 

 In Myxosoma and Myxobolus, the spore sometimes develops a short 

 posterior process, which is highly developed in the spore of the genus 

 Henneguya. 



Young spores, generally speaking, are more rounded in form than the 

 mature form, while the mature spores, as a rule, are of definite form, 

 structure and size characteristic to the species. It should, however, be 

 kept in mind that there is a certain amount of variation among these 

 characters. 



As is generally recognized, one must mention whether the spores were 

 measured in fresh condition or in fixed and stained state. The fresh spore 

 is generally more or less larger than the mounted one. 



